Can Delicate Blue-Eye and Long-Finned African Tetra Live Together?

Reviewed by Guidarium Editorial DeskUpdated May 6, 2026
Possible with Caution

Keeping Delicate Blue-Eye and Long-Finned African Tetra together is possible but requires caution, though some care is needed. Provide a spacious tank of at least 200 litres with plenty of hiding spots to reduce stress. Monitor behaviour closely, especially during the first few weeks.


At a Glance

Delicate Blue-Eye

Pseudomugil tenellus

Long-Finned African Tetra

Brycinus longipinnis

🐠Family Group
Delicate Blue-Eye
Rainbowfish
Long-Finned African Tetra
Characins
Temperament
Delicate Blue-Eye
Peaceful (1/10)
Long-Finned African Tetra
Peaceful (2/10)
Temperature
✓ Compatible
Delicate Blue-Eye
25–32°C
Long-Finned African Tetra
22–26°C
pH Range
✓ Compatible
Delicate Blue-Eye
5–7.5
Long-Finned African Tetra
6–8
Hardness (dGH)
✓ Compatible
Delicate Blue-Eye
5–15
Long-Finned African Tetra
5–19
Water Type
✓ Compatible
Delicate Blue-Eye
Brackish Tolerant
Long-Finned African Tetra
Freshwater Only
Flow Preference
✓ Compatible
Delicate Blue-Eye
Moderate
Long-Finned African Tetra
High
Min Tank Volume
Combined: 200 L
Delicate Blue-Eye
60 L
Long-Finned African Tetra
200 L
Swimming Level
Shared: 2 zones
Delicate Blue-Eye
TopMiddle
Long-Finned African Tetra
TopMiddle
🏷️Behavior Tags
Delicate Blue-Eye
Nano / Bite-sized (Predation Risk)Hyperactive / Fast SwimmerJumper (Lid Required)Fry Predator
Long-Finned African Tetra
Hyperactive / Fast SwimmerJumper (Lid Required)Fry PredatorAggressive Eater (Starves shy fish)
Stocking calculator

Can your tank handle Delicate Blue-Eye and Long-Finned African Tetra?

Compatibility is only part of the answer. Test both fish with your real tank size, current stock, and maintenance needs to see if you have enough space and a safe stocking level before you add them.

Delicate Blue-Eye
Long-Finned African Tetra
Test both in my tank

Behaviour & Temperament

Delicate Blue-Eye is a peaceful species (1/10), while Long-Finned African Tetra is peaceful (2/10). This modest difference means Long-Finned African Tetra may occasionally assert dominance over Delicate Blue-Eye.

Delicate Blue-Eye and Long-Finned African Tetra both frequent the Top (Surface) and Middle (Open Water) region of the setup. This overlap can increase competition for space, so providing ample room and cover is important to keep both species comfortable.

Worth noting: Delicate Blue-Eye is a known jumper, so a tight-fitting lid is essential.

Water Parameters

The safe temperature window for both species falls between 25°C and 26°C. Aim for the midpoint of this range (around 25.5°C) for optimal comfort.

Both fish can tolerate a pH between 6 and 7.5. Maintaining a stable value within this band is more important than hitting an exact number.

For general hardness, the shared comfort zone is 5–15 dGH. Regular testing will ensure conditions stay within this range.

Tank Setup

To house Delicate Blue-Eye and Long-Finned African Tetra together, plan for an aquarium of at least 200 litres with a minimum length of 120 cm. This recommendation combines the stricter species minimums with a community-load allowance so the pairing has realistic long-term space and filtration headroom.

Because this pairing requires extra vigilance, include plenty of hiding spots — caves, driftwood, and dense plant clusters — so the less dominant fish can retreat when needed.

Specific environmental needs for this combination include: Plants - Densely covered, Plants - Floating, Driftwood (Digestion/Hiding). Meeting these requirements will help both species thrive.

Both species do well with moderate (standard) water movement, so a standard filtration setup rated for the tank volume should suffice.

Why This Pairing Needs Extra Planning in Practice

This pairing usually fails when the tank is treated like a standard mixed community and the caution flags are ignored. Delicate Blue-Eye and Long-Finned African Tetra need extra room, more cover, and closer observation during the first few weeks so small aggression, feeding, or territory issues do not snowball into a long-term problem.

Suitable Tank Sizes

Standard aquarium sizes large enough for both Delicate Blue-Eye and Long-Finned African Tetra.

Show 5 more tank sizes

Frequently Asked Questions

Can Delicate Blue-Eye and Long-Finned African Tetra live together?

They can coexist, but the pairing requires careful monitoring. Provide ample space (at least 200 litres), plenty of hiding spots, and watch for signs of stress or aggression.

What size tank do Delicate Blue-Eye and Long-Finned African Tetra need?

A minimum of 200 litres (tank length at least 120 cm) is recommended. This provides enough space for both species to establish their own areas and reduces the likelihood of territorial disputes.

What water temperature is best for Delicate Blue-Eye and Long-Finned African Tetra together?

Keep the aquarium between 25°C and 26°C. A target of around 25.5°C sits comfortably within both species' preferred ranges.

Are Delicate Blue-Eye or Long-Finned African Tetra aggressive?

Delicate Blue-Eye is peaceful (1/10) and Long-Finned African Tetra is peaceful (2/10). Their similar temperaments generally lead to a peaceful coexistence.

What pH do Delicate Blue-Eye and Long-Finned African Tetra need?

Both species overlap in the 6–7.5 pH range. Consistency is key — avoid sudden swings, and test regularly to stay within this window.

Editorial Review

Guidarium Editorial Desk

Reviewed against Guidarium care, stocking, and compatibility standards. Read the editorial policy.

Last reviewed
May 6, 2026
Last updated
May 6, 2026
Issues or corrections?
Contact the editorial team

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